Today's trend is to configure separate networks for management, virtual machines (VMs) and migration of VMs in virtual datacenters. Typically, in such virtual datacenters a set of virtualization-based distributed infrastructure services provides virtual machine monitoring and management to automate and simplify provisioning, optimize resource allocation, and provide operating system and application-independent high availability to applications at lower cost and without the complexity of solutions used with static, physical infrastructure and other such environments. One of these distributed services is, a failover service, which provides easy-to-manage, cost-effective (high availability) HA clusters for all applications running on VMs that are often used for critical databases, file sharing on a network, business applications, and customer services, such as electronic commerce websites. In the event of a server hardware failure, affected VMs are automatically restarted on other physical servers during a failover operation to reduce downtime and information technology (IT) service disruption and to further reduce any dedicated standby hardware and installation of additional software requirements.
However, if a host computing system is partially isolated (i.e., isolated from virtual machine and migration networks and not the management network) from the other host computing systems in an high availability (HA) cluster in the virtual datacenter, the failover operation may not perform any migration operations as the management is still running and the virtual center is able to interact with the isolated host computing system. In such a scenario, the VMs running on the isolated host computing system may not be accessible by any user as the host computing system is isolated from the VMs network.